Microsoft is running a promotion where anyone who's purchased a Windows 7 computer after June 2nd can buy a copy of Windows 8 for a mere $15 USD. Want in on the deal? You don't have to buy a Windows 7 computer…just tell Microsoft that you did.

As far as we can tell, the loophole has been open all weekend. To take advantage, all you have to do is go to Microsoft's upgrade page, fill out your details, and when the signup form asks when you purchased your new computer, just pick a date after June 2nd.

You'll be prompted to run the Windows 8 Upgrade Assistant on your system to make sure your computer meets the system requirements, but after that's finished, you'll get a promo code you can use to claim your $25 discount off of Windows 8's normal $40 retail price. To see a walkthrough of the process, hit the link below to see how The Next Web did it, and then go claim your copy before the promotion runs out (scheduled for January 31st) or Microsoft fixes the loophole, whichever comes first.